Not under the rules (EASA OPS) that are in effect around here. Would probably be the end of transatlantic flying.
Oh it is.
AMC1 CAT.OP.MPA.150(b) Fuel policy
(6) The minimum additional fuel, which should permit:
(i) the aeroplane to descend as necessary and proceed to an adequate alternate aerodrome in the event of engine failure or loss of pressurisation, whichever requires the greater amount of fuel based on the assumption that such a failure occurs at the most critical point along the route, and
(A) hold there for 15 minutes at 1 500 ft (450 m) above aerodrome elevation in standard conditions; and
(B) make an approach and landing,
except that additional fuel is only required if the minimum amount of fuel calculated in accordance with (a)(2) to (a)(5) is not sufficient for such an event;
It’s rarely necessary, because the trip + alternate + contingency fuel is usually sufficient to get to an enroute alternate from the most critical point. The example that I’ve come across is an oceanic ferry flight to a coastal destination where an alternate is not required, where the aircraft is light and the planned cruising level is high, so the penalty for depressurisation is greatest.
The same intent is repeated in Part-NCC and Part-NCO, though without the AMC to explain what it means.
NCO.OP.125 Fuel and oil supply — aeroplanes…
(b) In computing the fuel required including to provide for contingency, the following shall be taken into consideration:
…
(3) procedures for loss of pressurisation or failure of one engine while en-route, where applicable; and
(4) any other condition that may delay the landing of the aeroplane or increase fuel and/or oil consumption.
Well a little bit like alternates, across the Atlantic in a lot of turbine pressurised singles and light jets, this is an academic discussion only. There are no practical alternates and a flight down at 12k may not leave you with enough fuel to get to an airport.
However, on a ferry flight, you could use oxygen. A proper sealed mask works up to about 45k.
It’s the passengers who make it tricky…
Peter wrote:
However, on a ferry flight, you could use oxygen. A proper sealed mask works up to about 45k.
Depends how far you are from destination but yes, Pilot only oxygen will also last a lot longer than sharing with pax (if it is from one tank as it is on C510).
AdamFrisch wrote:
Same thing could happen on an airliner, I assume.
None that I am aware of. The Airbusses have manual uplock releases, so have the Boeings I think. Hydraulic failure won’t cause the gear to free-fall unless you use the
releases. I’d consider such a technology hugely unsafe.
172driver wrote:
ANZ will be flying a 777 with an ETOPS of 330 minutes (i.e. 5h30’) between ACK and EZE on a track that goes largely over the southern Pacific and skirts
Antarctica. Diversion fields? None. Hence the 330 mins……
This has been an “old” game over the pacific, where ETOPS has become longer and longer. Kind of makes it absurd. All this does in the end is to calculate the parameters to make sure you actually can fly for 5-30 on one engine. If you’d want to is another matter. I always found even 3 hours on a “wing and a prayer” kind of pushing it. For such routes I’d definitly prefer 3 or 4 engines.
Anyway I was not pointing towards a particular airline. I recall somehow being told that there also was a 330 operation someplace with 240 mins, I could be wrong but it might have been KAL, somewhere between Asia and the US.
Snoopy wrote:
Our ETP’s are calculated threefold for ETOPS planning
1 Engine Out
2 Decompression
3 Engine out and decompression
Thanks! I thought so, that is how I remember it.
Snoopy wrote:
As said, this is ETOPS planning, which albeit very important is quite theoretical. During actual flight you go to the nearest place with good weather and
infrastructure and will have plenty of fuel.
Well, there is quite a few ETOPS legs where the nearest field actually is the ETOPS location, such as over the NATL or PAC routes. Clearly, if you ETOPS in areas with other fields, such as in Africa, for the lack of weather or other requirements, then it becomes a mute exercise, as are most Stops calcs.
Still, I found the availability of ETP’s on any flight planning system a useful exercise. It probably saved one of our MD80’s some years ago which had a cockpit fire and on the basis of the ETP decided to turn back to Munich instead of coming to ZRH. With the outcome in MUC, the 5-10 minutes longer to ZRH could have been fatal.
Snoopy wrote:
More interesting inmho is flying routes over high terrain and the required escape routes to get down safely while evading grid moras up to the 300’s.
Up to the 300’s? Himalaya? We were never allowed to fly over that range, only around it. Are there operations which actually cross this? Wow. I did not really know that. A depress up there would be fatal in almost all cases.
I can’t find any cases of individual passenger windows blowing out, but apparently it’s been ‘done’ as a mythbuster’s test:
